High T_g fluoranthene-based electron transport materials for organic light-emitting diodes

Abstract

In this study, fluoranthene-based derivatives with a high thermal stability were synthesized for applications in organic electroluminescent devices. The two derivatives synthesized in this study, bis(4-(7,9,10-triphenylfluoranthen-8-yl)phenyl)sulfane (TPFDPS) and 2,8-bis(7,9,10-triphenylfluoranthen-8yl)dibenzo[b,d]thiophene (TPFDBT), were characterized by cyclic voltammetry, differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). TPFDPS exhibits a high T g of 210 1C while TPFDBT is crystalline in nature. Both the derivatives are thermally stable up to 500 1C. The charge transport studies reveal predominant electron transport properties. Subsequently, we fabricated blue OLEDs with 2-tert-butyl-9,10-bis-(b-naphthyl)-anthracene (TBADN) as the emitting layer to demonstrate the applications of these molecules as an electron transporting layer.

Luminescent‐Substituted Fluoranthenes—Synthesis, Structure, Electrochemistry, and Optical Properties

“…In this present study, we used substrates containing not only a single acetylene motif (Scheme ), but also substrates with two ethynyl motifs, thus allowing us to obtain products with two fluoranthene cores (Scheme ). This type of compound is usually obtained by using thermal Diels–Alder reactions of diacetylenes with cyclopentadienone derivatives . Ethynyl substrates, in our case, were obtained through a Sonogashira coupling of aryl halides with (trimethylsilyl)acetylene based on reported methods .…”

“…It is worth noting that the obtained values are significantly higher than for diphenyl fluoranthene with an indoloquinoxaline moiety at the 8 position ( Φ =14–17 %) . Compounds 2 c and 2 f containing a bithiophene unit at the peripheral position or in the core exhibit relatively low quantum yields ( Φ f =22 and 32 % for 2 c and 2 f , respectively), and these values are notably lower than for the described bis(fluoranthene) with diphenylsulphide and dibenzothiophene bridges ( Φ =77–79 %) …”

“…This type of compound is usually obtained by using thermal Diels-Alder reactions of diacetylenes with cyclopentadienone derivatives. [5,11,21] Ethynyl substrates, in our case, were obtained through aS onogashira coupling of aryl halides with (trimethylsilyl)acetylene based on reported methods. [22][23][24][25][26] Such as ynthetic path allowed ar elativelye asy introductiono ft he trimethylsilyl group to the fluoranthene core if necessary (simply by leaving the ethynyl group from the substrate protected).…”

Fluoranthene-Based Molecules as Electron Transport and Blue Fluorescent Materials for Organic Light-Emitting Diodes

“…The synthesis of compounds TPFDPS, and TPFDBT are described in our earlier report. 49 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 TPFDBTO2, exhibit strong blue emission peak at 460 nm and 454 nm in solution and DPEPO matrix, respectively. The PLQY (φ) of these compounds were found to be very high in the solution but quite low in the neat films.…”

“…[38][39][40][41][42][43][44][45][46][47] Li et al reported the synthesis of heterocyclic fused fluoranthene derivatives, tetraazabenzodifluoranthne dimides, as potential electron acceptor materials in solar cells. 48 In our earlier report, we have observed very high thermal stability and predominant n-type character for fluoranthene derivatives, bis(4-(7,9,10-triphenylfluoranthen-8-yl)phenyl)sulfane (TPFDPS) and 2,8-bis (7,9,10- 49 We have explored these molecules as electron transport materials for OLEDs using 2-tert-Butyl-9,10-di(naphth-2-yl)anthracene (TBADN) as the active layer, N,N'-diphenyl-N,N'-bis (3-methylphenyl)(1,1'-biphenyl)-4,4'-diamine (TPD) as hole transport layer, in a tri-layer device configuration; and achieved moderate device efficiencies. In this report, we have extended our studies to use modified fluoranthene derivatives as both electron transport as well as light emitting layer for OLEDs, thus simplifying the device architecture by minimizing the number of layers.…”